01 kx65 mid range power

[stuntmanx8]

Greetings folks,

I'm not new to 2 cycle bikes, however I am new to minis. I picked up a really great running little kx65 for my boy to bomb around on and to be my little pit bike. Perhaps this issue is common for the little bikes, but this thing has pretty much zero mid range power. Once it comes on the pipe and hits that power band, it's a little rocket.

Set up is stock to my knowledge with a fmf gold fatty pipe and PC r-304 silencer. Not sure why this combo was chosen by the previous owner, but I can't help but wonder if it's a jet setting issue or just common for this little bike to only have top end.

I'm running 93 oct pump gas and mixing it at 32:1 since I hear the bottom ends need more oil. Bike doesn't smoke much, fires up 1st or second kick every time and seems to run well other than this issue of not much midrange.

[moose_338]

Little two strokes have not much else but top end. You can try finding a reed cage spacer or a flywheel weight, either one of both would tone it done some. I would suggest maybe adding a tooth or two to the rear sprocket to get him up into the power sooner.

[turbo dan]

About all you could really do is turn down the cylinder base on a lathe and mill the head to accommodate the new deck height and reset the squish.  Sounds like it's running right though.  That's what makes small bores fun. 

[tchetek]

I rebuilt an 03 this spring.

Started with stock jetting. Was a bit rich for our location. One clip on the needle widened our power band a fair bit for us.


Was gonna experiment with pilot and main, but it’s been running great all summer so stopped wrenching and let the boys burn fuel!

Check your jetting. Check your plug. Compare to stock.

Our bikes stock except we gave the 2 stage reeds a try.

[stuntmanx8]

Thanks for all the feed back and input. I will have to look and see what this thing is jetted at. I did changed the plug temp from a 10 to a 8. It appears to be cleaning much better with less black on the plug end.

[Motox367]

Not good pitbike for full grown man. To much weight will wanna just wheelie cause its all or nothing power wise

[moose_338]

1 hour ago, Motox367 said:

Not good pitbike for full grown man. To much weight will wanna just wheelie cause its all or nothing power wise

read the op again

[Motox367]

13 minutes ago, moose_338 said:

read the op again

Ya and?

[moose_338]

11 minutes ago, Motox367 said:

Ya and?

It's also for his kid and I am sure he already knows what you had to point out.

[Motox367]

31 minutes ago, moose_338 said:

It's also for his kid and I am sure he already knows what you had to point out.

So whats your problem then?

[stuntmanx8]

I am fully aware this bike will never perform like a 4stroke pit bike.

Thanks

[kxrob]

On 9/9/2018 at 8:36 AM, stuntmanx8 said:

Greetings folks,

I'm not new to 2 cycle bikes, however I am new to minis. I picked up a really great running little kx65 for my boy to bomb around on and to be my little pit bike. Perhaps this issue is common for the little bikes, but this thing has pretty much zero mid range power. Once it comes on the pipe and hits that power band, it's a little rocket.

Set up is stock to my knowledge with a fmf gold fatty pipe and PC r-304 silencer. Not sure why this combo was chosen by the previous owner, but I can't help but wonder if it's a jet setting issue or just common for this little bike to only have top end.

I'm running 93 oct pump gas and mixing it at 32:1 since I hear the bottom ends need more oil. Bike doesn't smoke much, fires up 1st or second kick every time and seems to run well other than this issue of not much midrange.

might be worth moving the clip up and shimming under clip with a wash to make it 1/2 clip leaner , the 2 stroke on/off all or nothing can come from the lean to rich to clearing out transition from pilot to needle taper  etc.  

[FaceDeAce]

Ya, our experience with the kx65 was much the same. It is a light switch, no dimmer. Full on, full off.
I added a flywheel weight to it. That delayed and smoothed out the hit quite a bit.